Neuroendocrine effects of bromperidol

In the present study we have considered the influence of various antipsychotic drugs (mostly butyrophenones) on some neuroendocrine axes (hypothalamic-hypophyseal-gonadal, hypothalamic-hypophyseal-thyroidal and hypothalamic-hypophyseal-prolactin axes). The antagonistic activity of bromperidol on DA receptors regulating the hypothalamic LH-RH release was compared in vitro to that of haloperidol. To support the possible inhibitory role of DA neurons on HHTA activity, we have evaluated the capacity of bromperidol to remove the apomorphine induced blockade of cold stress-stimulated TSH release. Finally, to evaluate the influence of the drug on prolactin release, bromperidol was compared with haloperidol and pimozide in adult male rats. The results obtained show that bromperidol is able to antagonize as well as haloperidol the DA-induced LH-RH release. The butyrophenone partially remove, in contrast to pimozide, the inhibitory effect of L-DOPA and apomorphine on TSH release. In in vivo and in vitro experiements the antidopaminergic action of bromperidol, evaluated by PRL release, can be considered intermediate between pimozide and haloperidol.